Composite thermal insulation pipe shell and installation method thereof

Abstract

The composite heat preservation pipe shell comprises a working steel pipe, a heat preservation layer is arranged on the outer layer of the working steel pipe, a protection layer is arranged on the outer layer of the heat preservation layer, a hot melting groove is formed in one end of the protection layer and located between the protection layer and the heat preservation layer, and a hot melting groove is formed in one side of the hot melting groove. And a hot melting ring matched with the hot melting groove is installed at the other end of the protective layer, accurate butt joint of the two sets of working steel pipes can be guaranteed by arranging the hot melting groove and the hot melting ring, and gaps caused by deviation in the butt joint process are avoided. The device has the beneficial effects that the inner side of the first electric heating wire is exposed in the hot melting groove, the inner wall and the outer wall of the hot melting ring can be subjected to hot melting with the two inner walls of the hot melting groove correspondingly, therefore, the connection strength between the hot melting groove and the hot melting ring is improved, the sealing effect between the hot melting groove and the hot melting ring is improved, operation and construction are easy, and the device is suitable for popularization and application. And the construction efficiency is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of butt joint installation of thermal insulation pipes, in particular to a composite thermal insulation pipe shell and an installation method thereof. Background Art

[0002] A thermal insulation pipe is short for an adiabatic pipeline. Thermal insulation pipes are used for the transportation of liquids, gases and other media, and are used for the adiabatic engineering insulation of pipelines in petroleum, chemical industry, aerospace, hot springs, military, central heating, central air conditioning, municipal engineering, etc. Thermal insulation pipes are suitable for transporting various media within the range of -50°C to 150°C. It is widely used in the thermal insulation and cold insulation projects of central heating, cooling, hot oil transportation, greenhouse, cold storage, coal mine, petroleum, chemical industry and other industries. Because the polyurethane rigid foam thermal insulation layer of the thermal insulation pipe is closely bonded to the outer skin of the steel pipe, it isolates the infiltration of air and water and can play a good anti-corrosion role. At the same time, its foaming holes are all closed, with very little water absorption. The high-density polyethylene outer shell and the fiberglass outer shell both have good anti-corrosion, insulation and mechanical properties. Therefore, it is very difficult for the outer skin of the working steel pipe to be eroded by external air and water. As long as the water quality inside the pipeline is well treated, according to foreign data, the service life of prefabricated directly buried high-temperature thermal insulation pipes can reach more than 50 years, which is 3 to 4 times higher than that of traditional trench laying and overhead laying.

[0003] The outside of a composite thermal insulation pipe usually uses an outer shell to play a protective role, and the inside is usually filled with thermal insulation materials to improve the thermal insulation performance of the pipeline. Since the laying length of thermal insulation pipes is generally long, it is usually necessary to butt joint the thermal insulation pipes to meet the laying length requirements. In order to ensure the connection strength of the butt-jointed pipes, some existing thermal insulation pipe shells generally use hot melt butt joint. However, this method not only requires high construction technology, but also has great difficulty in detecting internal defects (such as pores, lack of fusion) in the hot melt layer of the pipeline later, and relies on professional detection equipment (such as ultrasonic waves, X-rays), resulting in high costs. Summary of the Invention

[0004] The purpose of the present invention is to overcome the disadvantages that some existing thermal insulation pipe shells using hot melt butt joint not only require high construction technology, but also have great difficulty in detecting the internal air tightness of the hot melt layer of the pipeline later, rely on professional detection equipment, and result in high costs, and provide a composite thermal insulation pipe shell and an installation method thereof.

[0005] The object of the present invention is achieved by the following technical solutions: a composite insulation pipe shell and its installation method, including a working steel pipe, an insulation layer is arranged on the outer layer of the working steel pipe, a protective layer is arranged on the outer layer of the insulation layer, a hot melt groove is installed at one end of the protective layer, the hot melt groove is located between the protective layer and the insulation layer, a hot melt groove is opened on one side of the hot melt groove, and a hot melt ring adapted to the hot melt groove is installed at the other end of the protective layer. By setting the hot melt groove and the hot melt ring, the accurate butt joint of two groups of working steel pipes can be ensured, and the deviation during the butt joint process can be avoided, so as to prevent the occurrence of gaps.

[0006] A spiral first heating wire is installed on the inner wall of the hot melt groove, the first heating wire is flush with the inner wall of the hot melt groove, and the inner side of the first heating wire is exposed inside the hot melt groove. By setting the inner side of the first heating wire to be exposed inside the hot melt groove, the inner and outer walls of the hot melt ring can be respectively melted with the two inner walls of the hot melt groove, thereby improving the connection strength between the hot melt groove and the hot melt ring, improving the sealing effect between the hot melt groove and the hot melt ring, and the operation and construction are simple. The hot melt groove, the hot melt ring and the first heating wire are all located inside the protective layer and are not affected by the external environment during the butt joint processing, effectively improving the construction efficiency.

[0007] An operation groove is opened on the upper part of the protective layer, and a first conductive interface connected to the hot melt groove is installed in the operation groove.

[0008] A detection cavity communicating with the hot melt groove is opened inside the hot melt groove, the detection cavity is arranged inside the hot melt groove, and an air inlet pipe extending into the operation groove is installed on the upper part of the detection cavity.

[0009] A further technical solution is that an annular block is installed between the hot melt groove and the detection cavity, a second heating wire is installed in the block, and the second heating wire is connected to a second conductive interface in the operation groove.

[0010] A further technical solution is that the inner diameter of the hot melt ring is larger than the outer diameter of the insulation layer. By setting the inner diameter of the hot melt ring to be larger than the outer diameter of the insulation layer, the hot melt ring can wrap the working steel pipe and the insulation layer after being butted with the hot melt groove, thereby ensuring the airtightness of the working steel pipe and the insulation layer, and avoiding groundwater from penetrating into the protective layer to corrode the working steel pipe and the insulation layer when the pipeline is laid underground, ensuring the service life of the pipeline.

[0011] A further technical solution is that the protective layer, the hot melt groove, the hot melt ring and the block are all made of high-density polyethylene. Setting the protective layer, the hot melt groove, the hot melt ring and the block to be all made of high-density polyethylene can make the pipeline have high strength and corrosion resistance, and improve the service life of the pipeline.

[0012] A further technical solution is that an air layer is provided between the heat insulation layer and the protective layer. Multiple groups of support frames are installed at equal distances in the air layer. Both ends of the support frames are respectively connected to the heat insulation layer and the protective layer. The combination of the air layer and the support frames can not only save materials and reduce costs, but also the air layer has a certain heat insulation effect while the support frames ensure strength, thereby further improving the heat insulation effect of the pipeline.

[0013] A further technical solution is that a sealing cap is installed at the air inlet end of the air inlet pipe.

[0014] A further technical solution is that an upper ferrule and a lower ferrule are installed at the butt joint of two groups of protective layers. The upper ferrule and the lower ferrule are connected by fastening bolts. The inner walls of the upper ferrule and the lower ferrule are both in contact with the outer wall of the protective layer. The setting of the upper ferrule and the lower ferrule can protect the outside of the butt joint of two groups of working steel pipes, and further improve the sealing performance and strength of the butt joint of two groups of working steel pipes.

[0015] A further technical solution is that a reserved groove corresponding to the operation groove is formed on the upper ferrule, and a clamping plate is installed on the reserved groove. The clamping plate is connected to the lower ferrule by fastening bolts. The setting of the reserved groove and the clamping plate can improve the convenience during construction.

[0016] An installation method of a composite heat insulation pipe shell is characterized by including the following steps:

[0017] S1 Pipeline butt joint: Butt joint two groups of working steel pipes to be butted, insert the hot melt ring at one end of the outer layer of one group of working steel pipes into the hot melt groove provided on the outer layer of the other group of working steel pipes, so that the protective layers on the outer layers of the two groups of working steel pipes are butted against each other without gaps. At this time, both the inner and outer walls of the hot melt ring are in contact with the inner wall of the hot melt groove and the first electric heating wire exposed on the inner wall of the hot melt groove, and one end of the hot melt ring is in contact with the stop block;

[0018] S2 Install the ferrule: Place the lower ferrule at the lower part of the butt joint of two groups of working steel pipes, place the upper ferrule at the upper part of the butt joint of two groups of working steel pipes, and fix the upper ferrule and the lower ferrule by fastening bolts. At this time, do not install the clamping plate so that the operation groove is in an exposed state;

[0019] Setting the upper ferrule and the lower ferrule to be installed before hot melting at the butt joint of two groups of working steel pipes can fix the outer wall of the pipeline, further tighten the pipeline, thereby avoiding the influence of pipeline thermal expansion on airtightness and further improving the hot melting effect of the pipeline.

[0020] S3 Hot melting: Connect the first conductive interface in the operation groove to an external power supply device to heat the first electric heating wire, control the heating temperature of the first electric heating wire to be 130°C - 135°C, and make the first electric heating wire generate heat to hot melt the inner wall of the hot melt groove and the outer wall of the hot melt ring in contact therewith;

[0021] S4 Air tightness detection: After waiting for the hot melt part to solidify, open the sealing cap, connect the air inlet end of the air inlet pipe to the digital display air inflation pump and inflate the detection cavity. Stop inflating when the air inflation pressure of the digital display air inflation pump shows 200Kpa. After 10 minutes, observe whether the displayed air pressure of the digital display air inflation pump decreases. If the displayed air pressure of the digital display air inflation pump remains unchanged, it indicates that the air tightness of the hot melt is good, and then proceed to S6. If the displayed air pressure of the digital display air inflation pump decreases, it indicates that there is a problem with the hot melt and air leakage exists, and then proceed to S5;

[0022] By setting the digital display air inflation pump to cooperate with the detection cavity, the hot melt effect between the hot melt groove and the hot melt ring can be quickly detected, which is easy to operate, has a low cost, and effectively improves the construction efficiency;

[0023] S5 Secondary hot melt: Connect the second conductive interface in the operation groove to an external power supply device to heat the second heating wire. Control the heating temperature of the second heating wire to be 135°C - 140°C. At the same time, turn on the digital display air inflation pump and continue to inflate the detection cavity until it reaches 200Kpa and then stop. Use the air pressure difference to fill the melted block into the air leakage point. At the same time, observe the displayed air pressure on the digital display air inflation pump. When the displayed air pressure remains unchanged, it indicates that the secondary sealing is completed, and then proceed to S6;

[0024] By setting the block and the second heating wire to cooperate, the block can be melted, and under the action of the high air pressure filled by the digital display air inflation pump, the air leakage point is filled. At the same time, the hot melt parts between the previous hot melt groove and the hot melt ring have cooled, and the molten material solidifies when passing through the air leakage point between the hot melt groove and the hot melt ring, thereby realizing the filling and sealing of the air leakage point, and thus realizing the secondary hot melt seal, effectively solving the problem of material waste and construction period delay caused by having to cut off the pipeline and re - operate after the welding fails.

[0025] S6 Installation completed: Pull out the digital display air inflation pump, install the sealing cap on the air inlet pipe, and finally install the clamping plate on the lower clamping sleeve through the fastening bolt to complete the butt - joint installation of the two groups of working steel pipes.

[0026] The present invention has the following advantages: 1. In the present invention, the inner side of the first heating wire is exposed inside the hot melt groove, which can hot melt the inner and outer walls of the hot melt ring with the two inner walls of the hot melt groove respectively, thereby improving the connection strength between the hot melt groove and the hot melt ring, improving the sealing effect between the hot melt groove and the hot melt ring, and the operation and construction are simple. The hot melt groove, the hot melt ring, and the first heating wire are all located inside the protective layer and are not affected by the external environment during the butt - joint processing, effectively improving the construction efficiency. Setting the inner diameter of the hot melt ring to be larger than the outer diameter of the insulation layer can enable the hot melt ring to wrap the working steel pipe and the insulation layer after being butted with the hot melt groove, thereby ensuring the air tightness of the working steel pipe and the insulation layer, and thus avoiding groundwater from seeping into the protective layer and corroding the working steel pipe and the insulation layer when the pipeline is laid underground, ensuring the service life of the pipeline.

[0027] 2. By installing an upper ferrule and a lower ferrule before the hot melt at the butt joint of two groups of working steel pipes, the outer wall of the pipeline can be fixed and the pipeline can be further tightened, thus avoiding the influence of the heat expansion of the pipeline on the airtightness and further improving the hot melt effect of the pipeline. By setting a digital display air pump to cooperate with the detection cavity, the hot melt effect between the hot melt groove and the hot melt ring can be quickly detected, which is easy to operate and has a low cost, effectively improving the construction efficiency and effectively solving the problems of material waste and construction period delay caused by the need to cut off the pipeline and re-operate after the welding failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic cross-sectional structure diagram of the working steel pipe in the present invention;

[0029] Figure 2 It is a schematic three-dimensional structure diagram of the working steel pipe in the present invention;

[0030] Figure 3 It is a schematic cross-sectional view of the butt joint state of the working steel pipe in the present invention;

[0031] Figure 4 In the present invention Figure 1 An enlarged schematic diagram of the A structure;

[0032] Figure 5 It is a schematic three-dimensional diagram of the disassembled state of the clamping plate in the present invention;

[0033] Figure 6 It is a schematic three-dimensional diagram of the installed state of the clamping plate in the present invention

[0034] In the figure, 1, working steel pipe; 2, heat insulation layer; 3, protective layer; 4, hot melt groove; 5, hot melt recess; 6, hot melt ring; 7, fastening bolt; 8, detection cavity; 9, stop block; 10, operation groove; 11, first conductive interface; 12, second conductive interface; 13, intake pipe; 14, sealing cap; 15, first heating wire; 16, second heating wire; 17, air layer; 18, support frame; 19, upper ferrule; 20, lower ferrule; 21, reserved groove; 22, clamping plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0036] Accordingly, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0037] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0038] It should be noted that like reference numerals and letters indicate like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0039] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for descriptive distinction and should not be construed as indicating or implying relative importance.

[0040] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] As Figures 1 to 6 shown, a composite insulation pipe shell includes a working steel pipe 1. An insulation layer 2 is provided on the outer layer of the working steel pipe 1. A protective layer 3 is provided on the outer layer of the insulation layer 2. A hot melt groove 4 is installed at one end of the protective layer 3. The hot melt groove 4 is located between the protective layer 3 and the insulation layer 2. A hot melt recess 5 is formed on one side of the hot melt groove 4. A hot melt ring 6 adapted to the hot melt recess 5 is installed at the other end of the protective layer 3. By providing the hot melt recess 5 and the hot melt ring 6, accurate docking of two groups of working steel pipes 1 can be ensured, and offset during docking and resulting gaps can be avoided.

[0042] The inner wall of the hot-melt groove 5 is provided with a spiral first heating wire 15. The first heating wire 15 is flush with the inner wall of the hot-melt groove 5, and the inner side of the first heating wire 15 is exposed inside the hot-melt groove 5. By setting the inner side of the first heating wire 15 to be exposed inside the hot-melt groove 5, the inner and outer walls of the hot-melt ring 6 can be hot-melted with the two inner walls of the hot-melt groove 5 respectively, thereby improving the connection strength between the hot-melt groove 5 and the hot-melt ring 6, enhancing the sealing effect between the hot-melt groove 5 and the hot-melt ring 6, and the operation and construction are simple. The hot-melt groove 5, the hot-melt ring 6, and the first heating wire 15 are all located inside the protective layer 3 and are not affected by the external environment during the butt joint processing, effectively improving the construction efficiency;

[0043] An operation groove 10 is opened in the upper part of the protective layer 3, and a first conductive interface 11 connected to the hot-melt groove 5 is installed in the operation groove 10;

[0044] A detection cavity 8 communicating with the hot-melt groove 5 is opened inside the hot-melt groove 4. The detection cavity 8 is arranged inside the hot-melt groove 4, and an air inlet pipe 13 extending into the operation groove 10 is installed in the upper part of the detection cavity 8.

[0045] An annular baffle 9 is installed between the hot-melt groove 5 and the detection cavity 8. A second heating wire 16 is installed inside the baffle 9, and the second heating wire 16 is connected to a second conductive interface 12 in the operation groove 10.

[0046] The inner diameter of the hot-melt ring 6 is larger than the outer diameter of the insulation layer 2. By setting the inner diameter of the hot-melt ring 6 to be larger than the outer diameter of the insulation layer 2, the hot-melt ring 6 can wrap the working steel pipe 1 and the insulation layer 2 after being butted with the hot-melt groove 5, thereby ensuring the airtightness of the working steel pipe 1 and the insulation layer 2, and avoiding groundwater from penetrating into the protective layer 3 to corrode the working steel pipe 1 and the insulation layer 2 when the pipeline is laid underground, ensuring the service life of the pipeline.

[0047] The protective layer 3, the hot-melt groove 4, the hot-melt ring 6, and the baffle 9 are all made of high-density polyethylene. Setting the protective layer 3, the hot-melt groove 4, the hot-melt ring 6, and the baffle 9 to be all made of high-density polyethylene can make the pipeline have high strength and corrosion resistance, and improve the service life of the pipeline.

[0048] An air layer 17 is arranged between the insulation layer 2 and the protective layer 3. Multiple groups of support frames 18 arranged at equal distances are installed inside the air layer 17. The two ends of the support frame 18 are respectively connected to the insulation layer 2 and the protective layer 3. The cooperation of the air layer 17 and the support frame 18 can not only save materials and reduce costs, but also the air layer 17 has a certain heat insulation effect while the support frame 18 ensures strength, thereby further improving the heat insulation effect of the pipeline.

[0049] A sealing cap 14 is installed at the air inlet end of the air inlet pipe 13.

[0050] At the butt joint of the two groups of protective layers 3, an upper ferrule 19 and a lower ferrule 20 are installed. The upper ferrule 19 and the lower ferrule 20 are connected by fastening bolts 7. The inner walls of the upper ferrule 19 and the lower ferrule 20 are in contact with the outer wall of the protective layer 3. The upper ferrule 19 and the lower ferrule 20 are provided to protect the outside of the butt joint of the two groups of working steel pipes 1, and further improve the sealing performance and strength of the butt joint of the two groups of working steel pipes 1.

[0051] A reserved groove 21 corresponding to the operation groove 10 is formed in the upper ferrule 19. A clamping plate 22 is installed on the reserved groove 21. The clamping plate 22 is connected to the lower ferrule 20 by a fastening bolt 7. The reserved groove 21 and the clamping plate 22 are provided to improve the convenience during construction.

[0052] An installation method of a composite thermal insulation pipe shell, characterized by comprising the following steps:

[0053] S1 Pipeline butt joint: Butt joint the two groups of working steel pipes 1 to be butted, insert the hot melt ring 6 at one end of the outer layer of one group of working steel pipes 1 into the hot melt groove 5 provided on the outer layer of the other group of working steel pipes 1, so that the protective layers 3 on the outer layers of the two groups of working steel pipes 1 are butted against each other without gaps. At this time, both the inner and outer walls of the hot melt ring 6 are in contact with the inner wall of the hot melt groove 5 and the first heating wire 15 exposed on the inner wall of the hot melt groove 5, and one end of the hot melt ring 6 is in contact with the stop block 9;

[0054] S2 Install ferrule: Place the lower ferrule 20 at the lower part of the butt joint of the two groups of working steel pipes 1, place the upper ferrule 19 at the upper part of the butt joint of the two groups of working steel pipes 1, and fix the upper ferrule 19 and the lower ferrule 20 by fastening bolts 7. At this time, the clamping plate 22 is not installed and the operation groove 10 is in an exposed state;

[0055] Setting the upper ferrule 19 and the lower ferrule 20 to be installed before hot melting at the butt joint of the two groups of working steel pipes 1 can fix the outer wall of the pipeline and further fasten the pipeline, thereby avoiding the influence of pipeline thermal expansion on airtightness and further improving the hot melting effect of the pipeline. S3 Hot melting: Connect the first conductive interface 11 in the operation groove 10 to an external power supply device to heat the first heating wire 15, control the heating temperature of the first heating wire 15 to be 130°C to 135°C, and make the first heating wire 15 generate heat to hot melt the inner wall of the hot melt groove 5 in contact with the outer wall of the hot melt ring 6;

[0056] S4 air tightness test: after waiting for the hot melt to solidify, open the sealing cap 14, connect the air inlet end of the air inlet pipe 13 to the digital display air pump to inflate the test chamber 8, and stop inflating when the air pressure of the digital display air pump displays 200Kpa. After 10 minutes, observe whether the displayed air pressure of the digital display air pump decreases. If the displayed air pressure of the digital display air pump remains unchanged, it means that the air tightness of the hot melt is good, and then proceed to S6. If the displayed air pressure of the digital display air pump decreases, it means that the hot melt is poor and there is air leakage, and then proceed to S5;

[0057] By setting a digital display air pump and cooperating with the detection chamber 8, the hot melting effect between the hot melting groove 5 and the hot melting ring 6 can be quickly detected, which is easy to operate and has low cost, and effectively improves the construction efficiency;

[0058] S5 secondary hot melt: connect the second conductive interface 12 in the working groove 10 to the external power supply device to heat the second heating wire 16, and control the heating temperature of the second heating wire 16 to be 135°C to 140°C. The heating temperature of the second heating wire 16 is set higher than the heating temperature of the first heating wire 15 to ensure that the block 9 is in a molten state to facilitate the flow and filling to the leaking place. At the same time, start the digital display air pump to continuously inflate the detection cavity 8 until it reaches 200Kpa and stop. The inflation pressure of the digital display air pump can be adjusted according to the actual situation. The melted block 9 is filled into the leaking place by using the pressure difference. At the same time, observe the displayed air pressure on the digital display air pump. When the displayed air pressure remains unchanged, it means that the secondary sealing is completed. At this time, S6 is performed;

[0059] By setting the stopper 9 and the second electric heating wire 16 in cooperation, the stopper 9 can be melted, and the leaking part can be filled under the action of the high air pressure filled by the digital display air pump. At the same time, the hot melt groove 5 and the hot melt ring 6 have been cooled, and the molten material solidifies when it passes through the leaking part between the hot melt groove 5 and the hot melt ring 6, thereby achieving filling and sealing of the leaking part, thereby achieving secondary hot melt sealing, effectively solving the problem of cutting off the pipeline and re-operating after welding failure, resulting in material waste and construction delay.

[0060] S6 installation is completed: pull out the digital display air pump, install the sealing cap 14 on the intake pipe 13, and finally install the clamping plate 22 on the lower clamping sleeve 20 through the fastening bolts 7 to complete the docking installation of the two sets of working steel pipes 1.

[0061] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A composite thermal insulation pipe shell and an installation method thereof, comprising a working steel pipe (1), the outer layer of the working steel pipe (1) is provided with a thermal insulation layer (2), the outer layer of the thermal insulation layer (2) is provided with a protective layer (3), characterized in that: A hot melt groove (4) is installed at one end of the protective layer (3), the hot melt groove (4) is located between the protective layer (3) and the thermal insulation layer (2), a hot melt groove (5) is opened on one side of the hot melt groove (4), and a hot melt ring (6) adapted to the hot melt groove (5) is installed at the other end of the protective layer (3); The inner wall of the hot melt groove (5) is provided with a first electric heating wire (15) in a spiral shape, the first electric heating wire (15) is flush with the inner wall of the hot melt groove (5), and the inner side of the first electric heating wire (15) is exposed inside the hot melt groove (5); an operating groove (10) is provided on the upper part of the protective layer (3), and a first conductive interface (11) connected to the hot melt groove (5) is installed in the operating groove (10); The hot melt groove (4) is provided with a detection cavity (8) in communication with the hot melt groove (5); the detection cavity (8) is arranged on the inner side of the hot melt groove (4); an air intake pipe (13) extending into the working groove (10) is installed on the upper part of the detection cavity (8).

2. A composite thermal insulation pipe shell and installation method thereof according to claim 1, characterized in that: An annular stopper (9) is installed between the hot melt groove (5) and the detection cavity (8), a second heating wire (16) is installed in the stopper (9), and the second heating wire (16) is connected to a second conductive interface (12) in the working groove (10).

3. The composite thermal insulation pipe shell and the installation method thereof according to claim 2, characterized in that: The inner diameter of the hot melt ring (6) is greater than the outer diameter of the thermal insulation layer (2).

4. The composite thermal insulation pipe shell and the installation method thereof according to claim 1, characterized in that: The protective layer (3), the hot melt groove (4), the hot melt ring (6) and the stopper (9) are all made of high-density polyethylene.

5. The composite thermal insulation pipe shell and the installation method thereof according to claim 1, characterized in that: An air layer (17) is provided between the thermal insulation layer (2) and the protective layer (3), and a plurality of groups of support frames (18) arranged at equal distances are installed in the air layer (17), and two ends of the support frames (18) are respectively connected to the thermal insulation layer (2) and the protective layer (3).

6. The composite thermal insulation pipe shell and the installation method thereof according to claim 1, characterized in that: A sealing cap (14) is installed at the air inlet end of the air inlet pipe (13).

7. The composite thermal insulation pipe shell and the installation method thereof according to claim 1, characterized in that: An upper clamping sleeve (19) and a lower clamping sleeve (20) are installed at the joint of the two groups of protective layers (3); the upper clamping sleeve (19) and the lower clamping sleeve (20) are connected by a fastening bolt (7); and the inner walls of the upper clamping sleeve (19) and the lower clamping sleeve (20) are in contact with the outer wall of the protective layer (3).

8. The composite thermal insulation pipe shell and the installation method thereof according to claim 7, characterized in that: The upper clamping sleeve (19) is provided with a reserved groove (21) corresponding to the working groove (10), a clamping plate (22) is installed on the reserved groove (21), and the clamping plate (22) is connected to the lower clamping sleeve (20) through a fastening bolt (7).

9. A method for installing a composite thermal insulation pipe shell according to claim 1, characterized in that: The following steps are involved: S1 Pipeline docking: dock the two groups of working steel pipes (1) to be docked, so that the hot melt ring (6) at one end of the outer layer of one group of working steel pipes (1) is inserted into the hot melt groove (5) provided on the outer layer of the other group of working steel pipes (1), so that the protective layers (3) of the outer layers of the two groups of working steel pipes (1) are docked with each other without gap, at this time, the inner and outer walls of the hot melt ring (6) are in contact with the inner wall of the hot melt groove (5) and the first electric heating wire (15) exposed on the inner wall of the hot melt groove (5), and one end of the hot melt ring (6) is in contact with the stopper (9); S2: installing the ferrule: placing the lower ferrule (20) at the lower part of the joint between the two groups of working steel pipes (1), placing the upper ferrule (19) at the upper part of the joint between the two groups of working steel pipes (1), and fixing the upper ferrule (19) and the lower ferrule (20) by tightening the bolts (7). At this time, the clamping plate (22) is not installed so that the working groove (10) is exposed; S3 hot melting: connecting the first conductive interface (11) in the working groove (10) to an external power supply device to heat the first heating wire (15), controlling the heating temperature of the first heating wire (15) to be 130° C. to 135° C., so that the first heating wire (15) heats up to hot-melt the inner wall of the hot melting groove (5) and the outer wall of the hot melting ring (6) in contact with each other; S4 air tightness test: after the hot melt is solidified, open the sealing cap (14), connect the air inlet end of the air inlet pipe (13) to the digital display air pump and inflate the air into the detection chamber (8), and stop inflating when the air pressure of the digital display air pump displays 200Kpa. After 10 minutes, observe whether the air pressure displayed by the digital display air pump decreases. If the air pressure displayed by the digital display air pump remains unchanged, it means that the air tightness of the hot melt is good, and then proceed to S6. If the air pressure displayed by the digital display air pump decreases, it means that the hot melt is poor and there is air leakage, and then proceed to S5; S5 secondary hot melting: connect the second conductive interface (12) in the working groove (10) to an external power supply device to heat the second heating wire (16), control the heating temperature of the second heating wire (16) to 135°C to 140°C, and start the digital display air pump to continuously inflate the detection cavity (8) until it reaches 200Kpa, and use the air pressure difference to fill the melted stopper (9) to the leaking part, and observe the displayed air pressure on the digital display air pump at the same time. When the displayed air pressure remains unchanged, it means that the secondary sealing is completed, and then proceed to S6; S6 installation is completed: pull out the digital display air pump, install the sealing cap (14) on the air inlet pipe (13), and finally install the clamping plate (22) on the lower clamping sleeve (20) through the fastening bolts (7) to complete the docking installation of the two sets of working steel pipes (1).

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